Serum and Placental lactic dehydrogenase and alkaline phosphatase isoenzymes in normal pregnancy and in pre-eclampsia.

LDH isoenzymes and heat-stable alkaline phosphatase were studied in the serum and placental extract of 20 cases of pre-eclampsia and 10 normal pregnancies as a control. The starch-gel electrophoretic serum and placental isoenzymogram showed that LDH4 and LDH5 were the main isoenzymes in the placenta while LDH1 and LDH2 were the main isoenzymes in the serum in pre-eclampsia. The electrophoretic serum protein pattern in pre-eclamlobulins with decreased albumin fraction, while in the placenta, the albumin fraction was increased together with a decrease in the alpha-globulins. The electrophoretic pattern of serum alkaline phosphatase showed a main band of activity at the B-globulin zone in all cases of normal pregnancy and pre-eclampsia. In the placenta, two additional bands were detected.